1. Technical Field
The present invention relates to packaged electronic assemblies, and, more particularly, to a grounding clip for computer peripheral cards.
2. Description of the Related Art
Electronic devices such as computers, laptops, personal digital assistance (PDA's), etc. utilize various types of interfaces in order to exchange data and expand their capabilities. For example, personal computers utilize parallel, serial, and bus interfaces to connect to external devices and exchange data. Bus interfaces often take the form of a slot connected to a printed circuit board that contains electrical contacts, and are sized to receive peripheral cards designed to meet specific standards. Examples of such standards include the Industry Standard Architecture (ISA), the Peripheral Component Interconnect (PCI), and the Personal Computer Memory Card International Association (PCMCIA).
The PCMCIA standard has been extensively refined to provide the requirements for accommodating a variety of device types on the basic peripheral card format. Some of the devices that can be accommodated on the PCMCIA peripheral card include random access memory (RAM), EEPROMs, hard disk drives, fax/modems, etc. PCMCIA cards are relatively small in size, hence lending to popularity for use with laptops, PDA's, etc.
Peripheral cards, such as PCMCIA cards, can be constructed in various ways. A typical PCMCIA card includes a printed circuit board (PCB) containing various types of electronic components mounted thereon. For example, various controller chips or a central processing unit (CPU) chip can be mounted on the PCB. In addition, the PCB may include integrated circuitry formed thereon as part of a fabrication process. The PCB is subsequently encased within a protective metal cover. The protective metal cover includes an edge that contains a plurality of female electrical connectors. Electronic devices that receive PCMCIA cards include corresponding male connectors that establish an electrical connection between the PCMCIA card and the electronic device. Peripheral cards such as PCI and ISA cards, however, are constructed such that only the edge connectors that will subsequently be in contact with the electronic device, are exposed.
One of the major problems encountered in manufacturing and handling peripheral cards is the build-up of electrical charges on the PCB. For example, during the manufacturing process, the peripheral card must be handled and carried on multiple occasions. During this process an electrical charge is generated and built up on the peripheral card. The amount of charge generated and built up depends on the amount of handling and the environment in which the peripheral card is handled. Consequently, a peripheral card can be packaged and sold while bearing an electrical charge thereon. When the peripheral card is inserted into the host device (i.e. the computer or PDA), the charge flows into the host device through the edge connectors. Since the edge connectors are in direct electrical communication with various components in the host device, the discharge of electrical energy from the peripheral card can cause significant damage to the circuit, which can, on occasions, lead to failure of the host device.
The discharge of electrical energy from the peripheral card to the device can be eliminated, for example, by grounding the peripheral card prior to contacting it with the device. This has been typically accomplished by providing a conductive grounding clip on the peripheral card for purposes of engaging an appropriate grounding circuit on the device. For example, the PCMCIA standard provides for grounding clips at a fixed location along the side edge of the peripheral card. Such an arrangement, however, requires additional parts and increases manufacturing costs in order to properly route the requisite number of traces to the grounding edge of the peripheral card.
Accordingly, one disadvantage associated with current peripheral cards is the inadvertent build-up of electrical charges that can potentially destroy circuitry on the host device that will receive the peripheral card. Another disadvantage associated with current peripheral cards is the extended manufacturing steps traditionally required to properly provide a grounding point.